Unique FXP problems

[jayo]

Hey all

After reading through all similar problem threads none identify with my situation, so here goes.

Currently using v1.4.3b857 under Windows 98. Source server is an NCFTPd server, target server is a Serv-U FTP server for Winsock v4 behind a NAT, which prohibits passive access. Target server has NAT option checked and passive mode unchecked. "Use passive mode" in Proxy options is also unchecked, but I don't see how that matters as I don't use a proxy.

Trying to fxp any file from source to target produces the following:

List Complete.
TYPE I
200 Type okay.
TYPE I
200 Type set to I.
PASV
227 Entering Passive Mode (209,xxx,xxx,xxx,253,221)
PORT 209,xxx,x,xxx,253,221
200 PORT Command successful.
STOR test.file
150 Opening BINARY mode data connection for test.file.
RETR test.file
426 Data connection closed, receive file test.file aborted.
ABOR
Transfer Failed!

It used to happen whereby the target server always tried to force passive mode even though it didn't allow it, which meant file transfers stalled at 0. I'm pretty sure I've tried every alternative FXP method combination possible, but to no avail.

The most annoying thing about this is a friend of mine with his own account on the source server has no problems with the same site-to-site. He's behind a NAT himself though, so his site options are apparently different and mirroring them won't help me.

Thoughts? - jayo